Liezel van der Merwe

 Prof EM van der Merwe


Tel:      012 420-5379
Email:  [email protected]
Office: NS1, Room 3-39

Position:   Associate Professor
Academic qualification:  PhD (Chemistry)

NRF rating:  C2

Teaching

Undergraduate Physical Chemistry courses and BSc(Hons) Chemical Kinetics course

Modules: CMY 282, CMY 717

Research Interest

Modification, characterization and valorisation of South African industrial wastes, by-products and minerals. Depending on the raw material studied and the intended application, this may include studies on solid-state thermochemical reactions, solid-liquid conversions, wet and dry surface modification techniques as well as a variety of leaching studies. Specific emphasis to the fields of Thermal Analysis, Solid State Chemistry and Surface Characterization. The techniques that are mostly applied are thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray powder diffraction analysis (XRD), X-ray fluorescence (XRF), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), FT-IR spectroscopy, Raman spectroscopy, particle size distribution (PSD), surface area determinations (BET) and various wet chemical methods.

Please visit our Mineral Waste Beneficiation research group website.

Publications

For all publications, please click here: Google Scholar, Scopus, Researchgate.

Recent Journal Articles

Dennis Simbarashe Moyo, António Benjamim Mapossa, Melanie Rademeyer, Elizabet Margaretha van der Merwe and Walter Wilhelm Focke (2022) TGA investigation of the volatilisation of fipronil at elevated temperatures. Thermochimica Acta, 718, 179379. Available online https://doi.org/10.1016/j.tca.2022.179379

Dehouche, N., Kaci, M., Focke, W.W. and van der Merwe, L. (2022) Accelerated Photo‐Oxidation of Polyamide 11 Nanocomposites under Various Clays Nanofillers. Macromolecular Symposia 404: 2100352. Available online https://doi.org/10.1002/masy.202100352 

Grizelda du Toit, Elizabet M. van der Merwe, Richard A. Kruger, James M. McDonald and Elsabé P. Kearsley (2022) Characterisation of the Hydration Products of a Chemically and Mechanically Activated High Coal Fly Ash Hybrid Cement. Minerals, 12(2): 157. Available online https://doi.org/10.3390/min12020157.

Grizelda du Toit, Elizabet M. van der Merwe, Richard A. Kruger, James M. McDonald and Elsabé P. Kearsley (2022) Characterisation of the Hydration Products of a Chemically and Mechanically Activated High Coal Fly Ash Hybrid Cement.
Minerals, 12(2): 157. Available online https://doi.org/10.3390/min12020157

Barbara A. Castleman, Elizabet M. van der Merwe and Frédéric J. Doucet (2021) Thermochemical purification of talc with ammonium sulphate as chemical additive.
Minerals Engineering, 164:106815. DOI: https://doi.org/10.1016/j.mineng.2021.106815

Bernard M. Vilakazi, Jacobus B. Wagener and Elizabet M. van der Merwe (2020) A thermogravimetric investigation into the synthesis of CoF3 from Co3O4, Journal of Fluorine Chemistry, 240: 109638. DOI: 10.1016/j.jfluchem.2020.109638.

António B Mapossa, Alcides Sitoe, Walter W Focke, Homa Izadi, Elizabeth L du Toit, René Androsch, Chanita Sungkapreecha and Elizabet M. van der Merwe (2020) Mosquito repellent thermal stability, permeability and air volatility. Pest Management Science, 76(3): 1112-1120. DOI: 10.1002/ps.5623.

Mathibela E. Aphane, Frédéric J. Doucet, Richard A. Kruger, Leslie Petrik and Elizabet M. van der Merwe (2020) Preparation of sodium silicate solutions and silica nanoparticles from South African coal fly ash. Waste and Biomass Valorization, 11: 4403-4417. DOI: 10.1007/s12649-019-00726-6.

Mustapha Kaci, Nadjet Dehouche, Walter W. Focke and Elizabet M. van der Merwe (2019) A Degradation Study of Polyamide 11/Vermiculite Nanocomposites under Accelerated UV Test. Polymer Engineering and Science, 59: 2449-2457. DOI: 10.1002/pen.25115.

Sameera Mohamed, Keabetswe Lehong, Elizabet M. van der Merwe, Wladyslaw Altermann,  Frédéric J. Doucet (2019) Thermochemical treatment of Platinum Group Metal tailings with ammonium salts for major element recovery. Journal of Thermal Analysis and Calorimetry, 138: 2015-2033. DOI: 10.1007/s10973-019-08233-5.

Neil Hearne, Mark M. Turnbull, Christopher P. Landee, Elizabet M. van der Merwe, Melanie Rademeyer (2019) Halide-bi-bridged polymers of amide substituted pyridines and -pyrazines: Polymorphism, structures, thermal stability and magnetism. CrystEngComm, 19: 1910-1927. DOI: 10.1039/C9CE00071B.

G. du Toit, E. Kearsley, J. M. McDonald, R. A. Kruger, E. M. van der Merwe (2018)  Chemical and mechanical activation of hybrid fly ash cement. Advances in Cement Research, 30(9) 399-412.
DOI: 10.1680/jadcr.17.00156  

Linda C. Prinsloo, Elizabet M. van der Merwe and Lyn Wadley (2018) The thermal behaviour of silica varieties used for tool making in the Stone Age. Journal of Thermal Analysis and Calorimetry 131(2) 1135-1145.
DOI: 10.1007/s10973-017-6602-z

Elizabet M van der Merwe, Clarissa L. Gray, Barbara A Castleman, Sameera Mohamed, Richard A Kruger and Frédéric J Doucet (2017) Ammonium sulphate and/or ammonium bisulphate as extracting agents for the recovery of aluminium from ultrafine coal fly ash. Hydrometallurgy, 171, 185-190.
DOI: 10.1016/j.hydromet.2017.05.015

Sameera Mohamed, Elizabet M. van der Merwe, Wladyslaw Altermann and Frédéric J. Doucet (2017) Addendum to “Process development for elemental recovery from PGM tailings 1 by thermochemical treatment: Preliminary major element extraction studies using ammonium sulphate as extracting agent” [Waste Manage. 50 (2016), 334-345]. Waste Management, 66, 222–224.
DOI: 10.1016/j.wasman.2017.04.009

Frédéric J. Doucet, Sameera Mohamed, Nicole Neyt, Barbara A. Castleman, Elizabet M. van der Merwe (2016) Thermochemical processing of a South African ultrafine coal fly ash using ammonium sulphate as extracting agent for aluminium extraction. Hydrometallurgy, 166, 174-184.
DOI: 10.1016/j.hydromet.2016.07.017

Sameera Mohamed, Elizabet van der Merwe, Wladyslaw Altermann, Frederic Doucet (2016) Process development for elemental recovery from PGM tailings by thermochemical treatment: Preliminary major element extraction studies using ammonium sulphate as extracting agent. Waste Management, 50, 334–345.
DOI: 10.1016/j.wasman.2016.02.021

E M van der Merwe, L C Prinsloo, C L Mathebula, H C Swart, E Coetsee, F J Doucet (2014) Surface and bulk characterization of an ultrafine South African coal fly ash with reference to polymer applications. Applied Surface Science, 317, 73-83.

E M van der Merwe, C L Mathebula, L C Prinsloo (2014) Characterization of the surface and physical properties of South African coal fly ash modified by sodium lauryl sulphate (SLS) for applications in PVC composites. Powder Technology, 266, 70–78.

F J Doucet, T K Mlambo, E M van der Merwe, W Altermann (2014) Injection of coal fly ash slurry in deep saline formations for improved CO2 confinement – A theoretical concept. International Journal of Greenhouse Gas Control 25, 198–200.

Recent Conference Proceedings

Mustapha Kaci, Walter W. Focke and Elizabet M. van der Merwe (2018) The effects of unmodified vermiculite on photooxidation of polyamide 11 nanocomposites under accelerated UV test. 9th International Conference on “Times of Polymers and Composites”. AIP Conference Proceedings 1981, 020048-1–020048-4. Available online at https://doi.org/10.1063/1.5045910.

Elizabet M van der Merwe, Clarissa Gray, Richard A Kruger and Frédéric J Doucet (2017) Aluminium extraction from ultrafine coal fly ash by thermochemical processing with ammonium sulphate and/or ammonium bisulphate. Published in Proceedings of EuroCoalAsh2017, Brno, Czech Republic, 6-8 February, pp 101-106. Available online at http://www.fch.vut.cz/eca2017/ (ISBN 978-80-214-5469-9).

Frédéric J. Doucet, Elizabet  M. van der Merwe, Nicole Neyt and Linda C. Prinsloo (2015), Extraction of Aluminum and other Strategic Metals from Coal Fly Ash using a Novel Process and Low-cost Recoverable Reagent . In: Proceedings of the 2015 World of Coal Ash Conference, Nashville, Tennessee, USA, 5-7 May. Available online at http://www.flyash.info/2015/099-vandermerwe-2015.pdf.

Mathibela E. Aphane, Elizabet  M. van der Merwe, Frédéric J. Doucet and Leslie Petrik (2015), The Effect of Sulphuric Acid Concentration on the Removal of Reactive Aluminium from South African Coal Fly Ash. In: Proceedings of the 2015 World of Coal Ash Conference, Nashville, Tennessee, USA, 5‑7 May. Available online at http://www.flyash.info/2015/073-dutoit-2015.pdf.

Grizelda du Toit, Elizabet M. van der Merwe, Elsabé P. Kearsley, Mike McDonald and Richard A. Kruger (2015), Compressive Strength of Chemically and Mechanically Activated Aluminosilicate systems. In: Proceedings of the 2015 World of Coal Ash Conference, Nashville, Tennessee, USA, 5-7 May. Available online at http://www.flyash.info/2015/073-dutoit-2015.pdf.

E M van der Merwe, L C Prinsloo, C L Mathebula, H C Swart, E Coetsee, F J Doucet and R A Kruger (2014), Comparison between the surface and bulk characterization of an ultrafine South African coal fly ash. Published in Proceedings of EUROCOALASH 2014, Munich, Germany, 13-15 October, pp 265-280. Available online at https://www.vgb.org/shop/tb720-14.html  (ISBN 978‑3‑86875-805-4).

- Author Liezel van der Merwe

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